The present invention relates to a precision transducer for measuring linear positions, comprising a scale bearing a first electric winding and a slide movable with respect to the scale and bearing a second winding, the scale being constituted by a tensioned flexible band and the slide having guide means for the band. It is well known that, when one winding is energised to induce a signal in the other winding, the phase of the induced signal changes cyclically as the slide is moved and each 2.pi. change of phase corresponds to a known increment of displacement. By keeping track of the increments (counting them algebraically) the position of the slide can be determined. It is known also to measure fractions of an increment and some arrangements may employ more than one winding on the scale or slide.
In a known transducer of the aforesaid type, the scale band is guided through the slide by means of two pairs of V-shaped guides, one pair at each end of the slide. During the movement of the slide, the scale band can undergo deformation between the two pairs of guides, bringing one of its edges closer to, or moving it away from, the slide, so that the scale is not kept perfectly parallel to the slide and the signals induced in the winding of the slide can be distorted and give rise to errors of measurement.